1. Field of the Invention
This invention relates generally to lockable plugs, and more particularly to a plug structure for closing a fuel tank or a container and which has an interior compartment for storing articles along with a combination lock for selectively releasing the plug structure.
2. Brief Description of the Prior Art
Locking fuel tank caps are known in the art. Most locking fuel tank caps are operated only by their corresponding key in a manner which the cap closes off the open end of the fuel tank filler neck. These types of caps are popular for closing the filler neck of an automobile fuel tank to prevent theft of the fuel. But, they have no provision for a storage compartment for their key.
In addition, magnetic boxes for containing an extra set of keys are known which can be magnetically attached to vehicles in a hidden location, but they are easily detached by unauthorized person, and often fall off while driving.
U.S. Pat. No. 4,794,768 issued to Moser et al discloses a gas cap having a push button combination lock, but does not suggest a storage compartment in the cap.
U.S. Pat. No. 4,829,796 issued to Mr. Kim discloses a locking gas cap assembly which utilizes a rotating ring type of lock of the type often used on brief cases. The cap member is a ring shaped cap member having outwardly extending protrusions for engaging recesses in the wall of the filler neck of a fuel tank. Although it has a storage compartment for a key, there is shown a hollow cylindrical member threadedly attached at the bottom end of the cap which extends into the filler neck and may contain a key. The cap structure would not allow its use on present day fuel tank filler necks and the placement of the storage compartment into the filler neck would be undesirable.
In this known arrangement, the locking gas cap assembly has a lower portion configured to be removable, received on and closes a container or fuel tank filler neck, an intermediate portion above the lower portion defining an interior storage compartment adapted to contain articles such as keys, money, etc., a cap member rotatably secured above the storage compartment, and a push button combination lock mechanism mounted in the cap member. The locking mechanism has a reciprocating member which will engage the cap member with the intermediate portion upon depressing a correct series of buttons and will disengage the cap member from the intermediate portion when the correct series of buttons are not depressed. When the cap member is disengaged, it rotates freely to prevent removal of the cap assembly from the container and access to the hidden article and the container contents. When the cap member is engaged, the whole fuel tank plug structure can be rotated as a single unit allowing the fuel tank plug structure to be installed or removed from the container or fuel tank filler neck to gain access to the container and the storage compartment of the cap assembly.
But, the cap assembly includes a combination cap lock which may be selectively provided with an interior storage compartment for a key independent of the clogging of the fuel tank filler neck. Herein, it is noted that the clogging of the cap assembly to the filler neck is performed under the cooperation of a fixed plate, a ring having two protrusions and a supporting member integrally assembled into one another, and two recesses formed on the fuel filler neck in a manner which the protrusions are supported in the recesses, respectively. With this arrangement, is easy to fail to seal off the filler neck, and further the laziness of installing the storage compartment to the cap assembly nullifies the storage of an auxiliary key irrelevant to the clogging of the filler neck. As a result, the combination cap lock must be considered to be independent of the interior storage compartment for keys or articles.